Continuously variable all speed transmission

Abstract

A continuously variable all speed transmission apparatus employs a conically-shaped driven surface which is frictionally contacted by a taut endless compliant transmission member that extends to a circular power source such as the pedal hub of a bicycle. The driven surface is centered upon an axis upon which an axle is disposed that causes rotation of a wheel such as a bicycle wheel. A shifting mechanism moves the contact site of the transmission member axially along the driven surface, thereby producing variation in the rotational speed of the wheel. The transmission member includes a central wire and a series of rollers disposed upon the wire in a manner to rotate about the wire without moving longitudinally thereupon.

Having thus described my invention, what is claimed is: 
     
       1. A continuously variable all speed transmission apparatus comprising: a) a conically-shaped driven surface centered upon a horizontally disposed axis of rotation,   b) a circular power source rotating upon a shaft parallel to said axis of rotation,   c) an endless compliant transmission member oriented in a plane substantially orthogonal to said axis of rotation and having inside and outside perimeters, said inside perimeter tautly contacting both said conically-shaped surface and said power source, said transmission member being comprised of a central wire of endless loop configuration and a multitude of identical rollers installed upon said wire and adapted to rotate about said wire while resisting movement along the length of said wire, said transmission member being disposed in a manner to define upper and lower portions that move in opposite directions,   d) shifting means for moving said transmission member axially with respect to said axis of rotation while maintaining said inside perimeter in contact with said driven surface,   e) a housing which rotatably supports said conically-shaped driven surface,   f) track means associated with said housing for controlling the movement of said shifting means, and   g) spring-activated tensioning means interactive with said upper and lower portions of said transmission member to maintain said transmission member at a uniform tension.   
     
     
       2. The apparatus of claim 1 wherein said conically-shaped driven surface is a drum of frustro-conical shape bounded by opposed large and small plateau extremities. 
     
     
       3. The apparatus of claim 2 further comprising a shaft centered upon said axis of rotation and extending in joinder between said drum and a vertically disposed driven wheel. 
     
     
       4. The apparatus of claim 3 wherein said small extremity is directed away from said vertically disposed driven wheel. 
     
     
       5. The apparatus of claim 1 wherein the angle of taper of said conically-shaped driven surface ranges between 10 and 20 degrees. 
     
     
       6. The apparatus of claim 1 wherein said rollers are the outer components of assemblies comprising a stationary seating member which securely grips said wire and permits rotation thereupon of said outer component roller while preventing movement in the direction of elongation of said wire. 
     
     
       7. The apparatus of claim 6 wherein said seating member is comprised of two components which fit together upon said wire. 
     
     
       8. The apparatus of claim 7 wherein said roller is comprised of two components which fit together upon said seating member. 
     
     
       9. The apparatus of claim 1 wherein said circular power source is a pedal-equipped hub of a bicycle. 
     
     
       10. The apparatus of claim 1 wherein said shifting means is comprised of several pivotally interengaged U-shaped brackets. 
     
     
       11. The apparatus of claim 10 wherein said brackets are elongated in an arcuate path. 
     
     
       12. The apparatus of claim 11 wherein each bracket is provided with guide means that slidably engage said track means.